In the event of a chemical release, safety sirens in Contra Costa County's industrial corridor will sound to alert the public. If you hear the sirens, or are told to Shelter-in-Place, emergency officials recommend that you Shelter, Shut and Listen:
Contra Costa County has a Community Warning System in place that uses several tools to alert the public. If there is a chemical release with the potential to impact the community, the outdoor Safety Sirens located in the vicinity of the emergency will be sounded. The sirens will sound for about 3 minutes, and will be re-sounded periodically during the emergency. The sirens are tested on the first Wednesday of every month at 11:00 a.m. Safety sirens are located in the industrial corridor of the County from Oakley to Richmond. There are other CWS tools to alert people in case of an emergency in other areas.
Shelter-in-Place advisories are issued by emergency officials via the news media. County officials recommend tuning an AM radio to KCBS 740. NOAA weather radios in Contra Costa County with "SAME" functionality will also receive Shelter-in-Place alerts. (These radios have been provided to schools, childcare centers, hospitals, etc. in the industrial corridor to provide indoor alerting and information, but anyone can purchase a weather radio with SAME capabilities from a retail supplier. NWS radios will sound an alert tone, followed by a voice message about the chemical emergency. Consider adding a weather radio to your facility.)
The County also has a phone ringdown system that would automatically begin calling homes and businesses in the impacted area with pre-recorded instructions about what to do. Even unlisted numbers will receive this call in the impacted areas.
If emergency officials recommend that people in your area Shelter-in-Place, you should stay inside and encourage customers, vendors, and others to do the same. Allow people from outside to Shelter-in-Place in your facility. Begin implementing your site emergency plan. For a Shelter-in-Place emergency, you will need to stay inside until the chemical leak has stopped and winds have dissipated any vapors in the vicinity.
The sirens will sound initially for about three minutes. They will continue to be resounded periodically if the event continues. Shelter-in-Place alerts are also broadcast over weather radios in Contra Costa County, and the County operates a phone ringdown system that is activated for Shelter-in-Place alerts.
County officials will announce the All Clear via the news media, so keep monitoring KCBS 740. There is no separate Safety Siren signal for All Clear. The sirens were not designed to be heard indoors. The County will also reactivate its telephone ringdown system to begin calling numbers in the impacted area with the All Clear message, but it may take a little while to call all numbers.
After the All Clear is announced, Health Department officials recommend that you open your windows and doors and air out your building.
The sirens are tested on the first Wednesday of each month at 11:00 a.m. They only sound for about one minute during the test, but will sound for three minutes during a real event.